From the U.S. Government Accountability Office, www.gao.gov
Title: Depiction of the Global Carbon Cycle Changes Over Time
Description: In six steps, this animation depicts the changes that have
occurred over time to the global carbon cycle, including the amount of
carbon existing in and moving between the planet's major carbon
reservoirs before and after 1800.
Related GAO Work: GAO-11-71, Climate Engineering: Technical Status,
Future Directions, and Potential Responses
Issue date: July 28, 2011
[First screen]
This screen has the GAO logo and the following text: “Depiction of the
Global Carbon Cycle Changes Over Time,” “Animation to GAO-11-71,”
“Climate Engineering: Technical Status, Future Directions, and Potential
Responses.”
[Second screen]
This screen title, in a gray box at the bottom of the screen, reads: “1.
Pre-industrial landscape.” Also in the gray box it notes that “All
numbers are in gigatons of carbon.” The screen depicts a landscape
including four carbon reservoirs: the ocean labeled “oceanic,” the sky
labeled “atmospheric,” the land labeled “terrestrial,” and the layers
below the earth’s surface labeled “geological.”
[ Narrator: ] Carbon is the basic element of life on Earth. It resides
in many places and in every organism, from the depths of the oceans, to
the land and vegetation, and in the atmosphere. It is also found in
geological deposits well below the Earth’s surface.
[Third screen]
This screen title, in a gray box at the bottom of the screen, reads: “2.
Pre-industrial carbon reservoirs.” Also in the gray box it notes that
“All numbers are in gigatons of carbon.” The screen depicts the same
landscape and reservoir labels from the previous screen. Numbers appear
beside each label as follows: “oceanic, 38,700;” “atmospheric, 590;”
“terrestrial, 3,800;” and “geological, 7,180.”
[ Narrator: ] The amount of carbon estimated to have been contained in
the Earth’s major carbon reservoirs prior to the year 1800 is reflected
here. All figures are scientific estimates and are represented in
gigatons, or billions of tons, of carbon.
[Fourth screen]
The screen title, in a gray box at the bottom of the screen, reads: “3.
Pre-industrial flow of carbon.” Also in the gray box it notes that “All
numbers are in gigatons of carbon.” This screen depicts the same
landscape, labels, and numbers from the previous screen. Small gray dots
appear moving between several of the reservoirs to represent carbon
transfers, and black numbers appear beside them indicating the net
magnitude of those transfers. The dots are moving from “oceanic” to
“atmospheric” at .6 gigatons per year, from “atmospheric” to
“terrestrial” at .6 gigatons per year, and from “terrestrial” to
“oceanic” at .6 gigatons per year.
[ Narrator: ] In the years prior to 1800, transfers of carbon, or
“fluxes,” took place naturally between these different reservoirs. While
carbon moved back and forth between the reservoirs, the overall, or net,
direction of these fluxes annually is indicated by the movement of the
gray dots. Their overall, net magnitude is indicated by the small black
numbers beside them.
[Fifth screen]
The screen title, in a gray box at the bottom of the screen, reads: “4.
Arrival of the industrial age.” Also in the gray box it notes that “All
numbers are in gigatons of carbon.” The screen zooms in slightly and a
drawing of a city emerges on the land that is identified with a label
reading “industrialization.” Elements within the city include large
buildings, cars moving along streets, a plane flying above the city,
small black dots of coal being extracted from below the earth’s surface
through a tube, and grey clouds rising into the air.
[ Narrator: ] Industrialization changed the landscape. Extracting and
burning fossil fuels to power new modes of production and transportation
had a direct impact on the carbon cycle.
[Sixth screen]
The screen title, in a gray box at the bottom of the screen, reads: “5.
Industrial age effect on carbon cycle.” Also in the gray box it notes
that “All numbers are in gigatons of carbon.” The screen zooms out again
to reveal the previous landscape, which now includes the city. New red
dots appear alongside the gray dots to represent the effect of
industrialization on the carbon transfer, and red numbers appear beside
them indicating the magnitude of that effect. The dots move from
“atmospheric” to “oceanic” at 1.9 gigatons per year, and from
“atmospheric” to “terrestrial” at .2 gigatons per year. Red dots also
move out from the top of the city into the air at 6.4 gigatons per year.
Additionally, red numbers appear next to each carbon reservoir title to
represent the effect of industrialization on the amount of carbon in
that reservoir, as follows: “oceanic, +137,” “atmospheric, +187,”
“terrestrial, -20,” and “geological, -304.”
[ Narrator: ] The amount of carbon emitted by industrial processes is
estimated at 6.4 gigatons per year. Over time, this has affected both
the balance of carbon in the existing reservoirs, and the magnitude of
carbon fluxes between those reservoirs. The large red numbers indicate
the total changes to the carbon reservoirs since 1800. The red dots and
the smaller red numbers beside them indicate the annual impact of
industrialization on the carbon fluxes. Notice that the annual impact on
the flux between the oceanic and atmospheric reservoirs runs in the
opposite direction of the natural flux, and at a much greater magnitude.
In contrast, the annual impact on the flux between the atmospheric and
terrestrial reservoirs amplifies the natural flux.
[Seventh screen]
The screen title, in a gray box at the bottom of the screen, reads: “6.
Current carbon cycle.” Also in the gray box it notes that “All numbers
are in gigatons of carbon.” The gray and red dots merge, turn orange,
and move in the new net direction of the carbon transfers. Orange
numbers appear beside them to represent the net magnitude of those
transfers. The dots move from “atmospheric” to “oceanic” at 1.3 gigatons
per year, from “atmospheric” to “terrestrial” at .8 gigatons per year,
and from “terrestrial” to “oceanic” at .6 gigatons per year. Red dots
continue to emerge from the city at 6.4 gigatons per year.
[ Narrator: ] The net effect of the use of fossil fuels on the carbon
fluxes is reflected here. The movement of the orange dots indicates the
new net direction of the fluxes, and their net magnitude is listed
beside them. One result of this shifting carbon balance is increased
acidity of both the air and ocean water. Many in the scientific
community are also concerned about its cumulative effect on global
surface temperatures.